Quarterly report pursuant to Section 13 or 15(d)

Financing Agreements - Narrative (Details)

v3.7.0.1
Financing Agreements - Narrative (Details)
3 Months Ended 6 Months Ended
Mar. 31, 2017
USD ($)
Mar. 31, 2016
USD ($)
Mar. 31, 2017
USD ($)
Mar. 31, 2016
USD ($)
Sep. 30, 2016
USD ($)
Dec. 19, 2014
USD ($)
Dec. 15, 2014
Debt instrument [Line Items]              
Maximum ratio of Indebtedness to EBITDA allowed     3.5        
Minimum ratio of EBITDA to interest expense allowed     3.5        
Restricted cash and cash equivalent $ 3,300,000   $ 3,300,000   $ 800,000    
$700 revolving credit facility (excluding outstanding letters of credit)              
Debt instrument [Line Items]              
Line of credit facility, maximum borrowing capacity 353,200,000   353,200,000     $ 700,000,000.0  
Letters of Credit Outstanding, Amount 9,100,000   9,100,000        
Line of credit facility, remaining borrowing capacity $ 472,400,000   $ 472,400,000        
Weighted average interest rates 1.44% 1.46% 1.42% 1.35%      
Weighted average facility fee   0.21% 0.23% 0.19%      
Term loan              
Debt instrument [Line Items]              
Debt instrument, face amount           $ 180,000,000.0  
Weighted average interest rates 2.16% 1.76% 2.05% 1.61%      
$150 senior unsecured notes, net of discount (1)              
Debt instrument [Line Items]              
Debt instrument, face amount $ 150,000,000 $ 150,000,000 $ 150,000,000 $ 150,000,000      
Debt Issuance Costs, Net 700,000   700,000   800,000    
Other Financing Agreements              
Debt instrument [Line Items]              
Line of credit facility, maximum borrowing capacity 206,400,000   206,400,000        
Line of credit facility, amount utilized for bank guarantees 118,900,000   118,900,000        
$100 Series A Notes (2)              
Debt instrument [Line Items]              
Stated interest rate             4.60%
Debt instrument, face amount 100,000,000 $ 100,000,000 100,000,000 $ 100,000,000      
Debt Issuance Costs, Net 800,000   800,000   400,000    
Syndicated credit facility              
Debt instrument [Line Items]              
Line of credit facility, maximum borrowing capacity 150,000,000   150,000,000        
Adjustments for New Accounting Pronouncement [Member]              
Debt instrument [Line Items]              
Debt Issuance Costs, Net 1,100,000   1,100,000   $ 1,200,000.0    
Foreign Exchange Forward [Member] | Cash flow hedging              
Debt instrument [Line Items]              
Derivative, notional amount $ 50,000,000   $ 50,000,000